Limb Segment Recruitment as a Function of Movement Direction, Amplitude, and Speed

Schillings, Joost J.; Meulenbroek, Ruud G. J.; Thomassen, Arnold J.W.M.

doi:10.1080/00222895.1996.9941749

Cited by 20 publications

(10 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It could be that the method used to assess differences in timing of the joint motions was not particularly sensitive to timing differences, or perhaps the cyclic nature of the task may result in different coordination strategies that result in more simultaneous motions at the two joints. Previous research indicates that movement joint coupling is effected by whether a movement task is discrete or cyclic (Meulenbroek et al, 1993;Schillings et al, 1996).…”

Section: Timing Of Spine and Hip Jointsmentioning

confidence: 99%

“…However, there are two potential limitations to these studies. First, cross-correlation analyses may not be particularly sensitive to timing differences in co-varying waveforms, and second, joint coupling is effected by whether a movement task is discrete or cyclic (Meulenbroek et al, 1993;Schillings et al, 1996). Therefore, the timing of the spine and hip needs to be assessed explicitly in subjects performing discrete movement tasks.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Coordination and timing of spine and hip joints during full body reaching tasks

Thomas

Gibson

2007

Human Movement Science

View full text Add to dashboard Cite

Coupling of spine and hip joints during full body reaching tasks was investigated in sixteen participants (8 male & 8 female) who performed reaching tasks at comfortable and fast-paced movement speeds to three targets located in a para-sagittal plane. The participants paused at target contact for 500 ms and then returned to an upright posture. Three dimensional joint motions of the spine and hip were recorded using an electromagnetic tracking device. We found an effect of movement phase (i.e. reach and return) on the onset timing of the spine and hip joints. For most target locations and movement speeds, spine motion onset preceded hip motion onset during the reaching phase of the movement task. In the reach phase, when averaged across all movement conditions, spine joint motion preceded hip joint motion by an average of 48.9 ms. In contrast, in the return phase, hip joint motion preceded spine joint motion by an average of 63.0 ms. Additionally, when subjects were instructed to use either a knee flexion or knee extension strategy to perform the reaching tasks there was no effect of movement strategy on timing of the spine and hip. There was also no effect of target height on the spine hip ratio, but as movement speed increased, the spine/hip ratio decreased for all target locations due primarily to an increase in hip joint excursion. The findings indicate clear differences in onset timing of the spine and hip joints during reaching tasks that necessitate some forward bending of the trunk and that onset timing is reversed for the return to an upright posture.

show abstract

Section: Timing Of Spine and Hip Jointsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Coordination and timing of spine and hip joints during full body reaching tasks

Thomas

Gibson

2007

Human Movement Science

View full text Add to dashboard Cite

show abstract

“…Size and speed can be volitionally varied (Figure 1, stage 9) after learning while preserving letter shape and the shapes of the velocity profiles (Plamondon et al, 1997;Schillings et al, 1996;van Galen & Weber, 1998;Wann & Nimmo-Smith, 1990;Wright, 1993). Isochrony, the tendency for humans to write letters of different sizes in the same amount of time, is also an emergent property of model interactions (Thomassen & Teulings, 1985;Wright, 1993).…”

Section: ·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·-·~mentioning

confidence: 99%

A quantitative evaluation of the AVITEWRITE model of handwriting learning

Paine

Grossberg

Gemmert

2004

Human Movement Science

View full text Add to dashboard Cite

“…Size and speed can be volitionally varied (Figure 1.3,(9)) after learning while preserving letter shape and the shapes of the velocity profiles (Plamondon et al 1997;Schillings et al, 1996;van Galen & Weber, 1998;Wann & Nimmo-Smith, 1990;Wright, 1993). Isochrony, the tendency for humans to write letters of different sizes in the same amount of time, is also demonstrated (Thomassen & Teulings, 1985;Wright, 1993).…”

Section: Introductionmentioning

confidence: 99%

A neural model of cortico-cerebellar interactions during attentive imitation and predictive learning of sequential handwriting movements

Grossberg

Paine

2000

Neural Networks

View full text Add to dashboard Cite

Much sensory-motor behavior develops through imitation, as during the learning of handwriting by children. Such complex sequential acts are broken down into distinct motor control synergies, or muscle groups, whose activities overlap in time to generate continuous, curved movements that obey an inverse relation between curvature and speed. How are such complex movements learned through attentive imitation? Novel movements may be made as a series of distinct segments, but a practiced movement can be made smoothly, with a continuous, often bellshaped, velocity profile. How does learning of complex movements transform reactive imitation into predictive, automatic performance? A neural model is developed which suggests how parietal and motor cortical mechanisms, such as difference vector encoding, interact with adaptivelytimed, predictive cerebellar learning during movement imitation and predictive performance. To initiate movement, visual attention shifts along the shape to be imitated and generates vector movement using motor cortical cells. During such an imitative movement, cerebellar Purkinje cells with a spectrum of delayed response profiles sample and Jearn the changing directional information and, in turn, send that learned information back to the cortex and eventually to the muscle synergies involved. If the imitative movement deviates from an attentional focus around a shape to be imitated, the visual system shifts attention, and may make an eye movement, back to the shape, thereby providing corrective directional information to the arm movement system. This imitative movement cycle repeats until the corticocerebellar system can accurately drive the movement based on memory alone. A cortical working memory buffer transiently stores the cerebellar output and releases it at a variable rate, allowing speed scaling of learned movements which is limited by the rate of cerebellar memory readout. Movements can be learned at variable speeds if the density of the spectrum of delayed cellular responses in the cerebellum varies with speed. Learning at slower speeds facilitates learning at faster speeds. Size can be varied after learning while keeping the movement duration constant (isochrony). Context-effects arise from the overlap of cerebellar memory outputs. The model is used to simulate key psychophysical and neural data about learning to make curved movements, including a decrease in writing time as learning progresses; generation of unimodal, bell-shaped velocity profiles for each movement synergy; size and speed scaling with preservation of the letter shape and the shapes of the velocity profiles; an inverse relation between curvature and tangential velocity; and a Two-Thirds Power Law relation between angular velocity and curvature.

show abstract

Limb Segment Recruitment as a Function of Movement Direction, Amplitude, and Speed

Cited by 20 publications

References 18 publications

Coordination and timing of spine and hip joints during full body reaching tasks

Coordination and timing of spine and hip joints during full body reaching tasks

A quantitative evaluation of the AVITEWRITE model of handwriting learning

A neural model of cortico-cerebellar interactions during attentive imitation and predictive learning of sequential handwriting movements

Contact Info

Product

Resources

About